Standard staircase dimensions

 

There are some principles to be observed while designing a staircase for homes as listed below.

A- Step Proportioning.

The riser and tread of every step should be of regular dimensions throughout the length of the stair. The proportion between going and rise of stop should be carefully worked out so as to provide comfort and ease to the users.

The following rules should be followed for finding a suitable relation between going and rise of steps in stair.

1) Rise + Going = 400 to 450 mm.

2)  (2x Rise) + (Going) in mm = 550 to 600 mm

3) Going x Rise, both in mm = 40000 to 41000  Sq.mm

while designing steps ,take 300 mm going and 140 mm rise as a standard value. For every 20 mm deduction from tread ,add 10 mm to the rise.

The following dimensions of tread and rise are generally used for different buildings

1) Residential buildings 250x160 mm.

2) Public buildings such as theatres ,colleges, banks etc.

3) Industrial Buildings ,The tread should not less than 250mm and rise not more than 190 mm.

It should be noted that the rules given above only act as guide but the actual dimensions of tread and rise depend upon the space available height of building and layout of stair.

B- Pitch of stair

The pitch or slope of the stair should neither be more than 40 degree nor less than 25 degree for at ease ascend and descend by the users.

C- Width of the stair

The width of the stair should be such that a person going up can pass a person coming down without any difficulty. The minimum width of stair in a residential building should be 1 Meter whereas in case of public building a minimum width of 1.5 Meter is desirable.

D- Length of flight

The number of steps in a flight should not be more than 12 otherwise it becomes difficult to move up and down the flight and the minimum number in a flight should be 3.

E-Head Room

An sufficient head room must be provided .It should not be less than 2.14 m vertically or 1.5 m at right angles to the line of nosing.

F- Winders

They should be avoided as for as possible because they are liable to be dangerous and involve extra expenditure in construction. Winders are difficult to be carpeted and are especially unsuitable for public buildings. However,  they are to be provided when the area of the staircase is limited, In such cases , winders should be placed at the lower end of the flight.

In a quarter space ,i.e. 90 degree turn ,only three winders should be provided.

G- Hand rails and balustrades.

A staircase should be provided with a hand rail along with balustrade to provide assistance ,comfort and safety to the users. The height of hand rail should neither be more than 0.85 meter and nor less than 0.75 meter.

H-Materials of stair

The stair should be constructed of sound materials of  fire resisting quality. It should preferably be constructed of R.C.C according to building bye-laws being followed in locality.

I- Location of stair

The staircase should be located in such a position that it can be easily and speedily approachable. It should be provided in center of the building where enough light and ventilation is ensured specially at turning points in a staircase.

In residential building stair should be located near the main entrance and screened from outside for privacy. In public building it should preferably be located obvious from the main entrance.